There’s always MakeHuman. You get to do whatever the heck you want with those figures. Use them as is, modify them, redistribute them, sell them, whatever. I’ve been cannibalizing the heck out of MakeHuman figures to make clothing and accessories for the Genesis models. There are even low poly game model proxies included.

As long as you aren’t referencing the topology of the figure then that would be fine. If your 2D render is just a render of the wire frame mesh then that would not be ok. If you did the latter you would be bound by the same terms and conditions of that the original Genesis figure has.

You can re-do the topology of the Genesis figure, and in fact I think you’ll find you won’t get very far if you don’t redo the topology of the figure. However you are still bound by the same terms with your ‘new’ genesis figure as you would be with the original.

I hope this answers your questions.

Hopefully that’ll also clear things up to those wonder the same thing as I was.